e08-transforms: Transform functions

Description

normalOffset is a function that can be used as the
TRANSFORM argument in an alterMean operation, which adds
an offset to each value in the mean where the offset is chosen from a
normal distribution.

invGammaMultiple is a function that can be used as the
TRANSFORM argument in an alterSD operation, which multiplies
each standard deviation by a positive value chosen from an inverse gamma
distribution with parameters shape and scale.